1 files changed, 379 insertions, 0 deletions
diff --git a/tools/perf/util/symbol-minimal.c b/tools/perf/util/symbol-minimal.c
new file mode 100644
index 000000000..0a71d1463
--- /dev/null
+++ b/tools/perf/util/symbol-minimal.c
@@ -0,0 +1,379 @@
+#include "debug.h"
+#include "dso.h"
+#include "symbol.h"
+#include "symsrc.h"
+
+#include <errno.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <string.h>
+#include <stdlib.h>
+#include <byteswap.h>
+#include <sys/stat.h>
+#include <linux/zalloc.h>
+#include <internal/lib.h>
+
+static bool check_need_swap(int file_endian)
+{
+	const int data = 1;
+	u8 *check = (u8 *)&data;
+	int host_endian;
+
+	if (check[0] == 1)
+		host_endian = ELFDATA2LSB;
+	else
+		host_endian = ELFDATA2MSB;
+
+	return host_endian != file_endian;
+}
+
+#define NOTE_ALIGN(sz) (((sz) + 3) & ~3)
+
+#define NT_GNU_BUILD_ID	3
+
+static int read_build_id(void *note_data, size_t note_len, struct build_id *bid,
+			 bool need_swap)
+{
+	size_t size = sizeof(bid->data);
+	struct {
+		u32 n_namesz;
+		u32 n_descsz;
+		u32 n_type;
+	} *nhdr;
+	void *ptr;
+
+	ptr = note_data;
+	while ((ptr + sizeof(*nhdr)) < (note_data + note_len)) {
+		const char *name;
+		size_t namesz, descsz, remaining;
+
+		nhdr = ptr;
+		if (need_swap) {
+			nhdr->n_namesz = bswap_32(nhdr->n_namesz);
+			nhdr->n_descsz = bswap_32(nhdr->n_descsz);
+			nhdr->n_type = bswap_32(nhdr->n_type);
+		}
+
+		namesz = NOTE_ALIGN(nhdr->n_namesz);
+		descsz = NOTE_ALIGN(nhdr->n_descsz);
+
+		/* validate individually to avoid size_t overflow on 32-bit */
+		remaining = note_data + note_len - ptr - sizeof(*nhdr);
+		if (namesz > remaining || descsz > remaining - namesz) {
+			pr_warning("%s: oversized note: n_namesz=%u, n_descsz=%u\n",
+				   __func__, nhdr->n_namesz, nhdr->n_descsz);
+			break;
+		}
+
+		ptr += sizeof(*nhdr);
+		name = ptr;
+		ptr += namesz;
+		if (nhdr->n_type == NT_GNU_BUILD_ID &&
+		    nhdr->n_namesz == sizeof("GNU")) {
+			if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
+				size_t sz = min(size, descsz);
+				memcpy(bid->data, ptr, sz);
+				memset(bid->data + sz, 0, size - sz);
+				bid->size = sz;
+				return 0;
+			}
+		}
+		ptr += descsz;
+	}
+
+	return -1;
+}
+
+int filename__read_debuglink(const char *filename __maybe_unused,
+			     char *debuglink __maybe_unused,
+			     size_t size __maybe_unused)
+{
+	return -1;
+}
+
+/*
+ * Just try PT_NOTE header otherwise fails
+ */
+int filename__read_build_id(const char *filename, struct build_id *bid)
+{
+	int fd, ret = -1;
+	bool need_swap = false, elf32;
+	union {
+		struct {
+			Elf32_Ehdr ehdr32;
+			Elf32_Phdr *phdr32;
+		};
+		struct {
+			Elf64_Ehdr ehdr64;
+			Elf64_Phdr *phdr64;
+		};
+	} hdrs;
+	void *phdr, *buf = NULL;
+	ssize_t phdr_size, ehdr_size, buf_size = 0;
+
+	if (!filename)
+		return -EFAULT;
+
+	errno = 0;
+	if (!is_regular_file(filename))
+		return errno == 0 ? -EWOULDBLOCK : -errno;
+
+	fd = open(filename, O_RDONLY);
+	if (fd < 0)
+		return -1;
+
+	if (read(fd, hdrs.ehdr32.e_ident, EI_NIDENT) != EI_NIDENT)
+		goto out;
+
+	if (memcmp(hdrs.ehdr32.e_ident, ELFMAG, SELFMAG) ||
+	    hdrs.ehdr32.e_ident[EI_VERSION] != EV_CURRENT)
+		goto out;
+
+	need_swap = check_need_swap(hdrs.ehdr32.e_ident[EI_DATA]);
+	elf32 = hdrs.ehdr32.e_ident[EI_CLASS] == ELFCLASS32;
+	ehdr_size = (elf32 ? sizeof(hdrs.ehdr32) : sizeof(hdrs.ehdr64)) - EI_NIDENT;
+
+	if (read(fd,
+		 (elf32 ? (void *)&hdrs.ehdr32 : (void *)&hdrs.ehdr64) + EI_NIDENT,
+		 ehdr_size) != ehdr_size)
+		goto out;
+
+	if (need_swap) {
+		if (elf32) {
+			hdrs.ehdr32.e_phoff = bswap_32(hdrs.ehdr32.e_phoff);
+			hdrs.ehdr32.e_phentsize = bswap_16(hdrs.ehdr32.e_phentsize);
+			hdrs.ehdr32.e_phnum = bswap_16(hdrs.ehdr32.e_phnum);
+		} else {
+			hdrs.ehdr64.e_phoff = bswap_64(hdrs.ehdr64.e_phoff);
+			hdrs.ehdr64.e_phentsize = bswap_16(hdrs.ehdr64.e_phentsize);
+			hdrs.ehdr64.e_phnum = bswap_16(hdrs.ehdr64.e_phnum);
+		}
+	}
+	if ((elf32 && hdrs.ehdr32.e_phentsize != sizeof(Elf32_Phdr)) ||
+	    (!elf32 && hdrs.ehdr64.e_phentsize != sizeof(Elf64_Phdr)))
+		goto out;
+
+	phdr_size = elf32 ? sizeof(Elf32_Phdr) * hdrs.ehdr32.e_phnum
+			  : sizeof(Elf64_Phdr) * hdrs.ehdr64.e_phnum;
+	phdr = malloc(phdr_size);
+	if (phdr == NULL)
+		goto out;
+
+	lseek(fd, elf32 ? hdrs.ehdr32.e_phoff : hdrs.ehdr64.e_phoff, SEEK_SET);
+	if (read(fd, phdr, phdr_size) != phdr_size)
+		goto out_free;
+
+	if (elf32)
+		hdrs.phdr32 = phdr;
+	else
+		hdrs.phdr64 = phdr;
+
+	for (int i = 0; i < (elf32 ? hdrs.ehdr32.e_phnum : hdrs.ehdr64.e_phnum); i++) {
+		ssize_t p_filesz;
+
+		if (need_swap) {
+			if (elf32) {
+				hdrs.phdr32[i].p_type = bswap_32(hdrs.phdr32[i].p_type);
+				hdrs.phdr32[i].p_offset = bswap_32(hdrs.phdr32[i].p_offset);
+				hdrs.phdr32[i].p_filesz = bswap_32(hdrs.phdr32[i].p_filesz);
+			} else {
+				hdrs.phdr64[i].p_type = bswap_32(hdrs.phdr64[i].p_type);
+				hdrs.phdr64[i].p_offset = bswap_64(hdrs.phdr64[i].p_offset);
+				hdrs.phdr64[i].p_filesz = bswap_64(hdrs.phdr64[i].p_filesz);
+			}
+		}
+		if ((elf32 ? hdrs.phdr32[i].p_type : hdrs.phdr64[i].p_type) != PT_NOTE)
+			continue;
+
+		p_filesz = elf32 ? hdrs.phdr32[i].p_filesz : hdrs.phdr64[i].p_filesz;
+		/* ssize_t can go negative with crafted ELF p_filesz values */
+		if (p_filesz <= 0)
+			continue;
+		if (p_filesz > buf_size) {
+			void *tmp;
+
+			buf_size = p_filesz;
+			tmp = realloc(buf, buf_size);
+			if (tmp == NULL)
+				goto out_free;
+			buf = tmp;
+		}
+		lseek(fd, elf32 ? hdrs.phdr32[i].p_offset : hdrs.phdr64[i].p_offset, SEEK_SET);
+		if (read(fd, buf, p_filesz) != p_filesz)
+			goto out_free;
+
+		ret = read_build_id(buf, p_filesz, bid, need_swap);
+		if (ret == 0) {
+			ret = bid->size;
+			break;
+		}
+	}
+out_free:
+	free(buf);
+	free(phdr);
+out:
+	close(fd);
+	return ret;
+}
+
+int sysfs__read_build_id(const char *filename, struct build_id *bid)
+{
+	int fd;
+	int ret = -1;
+	struct stat stbuf;
+	size_t buf_size;
+	void *buf;
+
+	fd = open(filename, O_RDONLY);
+	if (fd < 0)
+		return -1;
+
+	if (fstat(fd, &stbuf) < 0)
+		goto out;
+
+	buf_size = stbuf.st_size;
+	buf = malloc(buf_size);
+	if (buf == NULL)
+		goto out;
+
+	if (read(fd, buf, buf_size) != (ssize_t) buf_size)
+		goto out_free;
+
+	ret = read_build_id(buf, buf_size, bid, false);
+out_free:
+	free(buf);
+out:
+	close(fd);
+	return ret;
+}
+
+int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
+	         enum dso_binary_type type)
+{
+	int fd = open(name, O_RDONLY);
+	if (fd < 0)
+		goto out_errno;
+
+	ss->name = strdup(name);
+	if (!ss->name)
+		goto out_close;
+
+	ss->fd = fd;
+	ss->type = type;
+
+	return 0;
+out_close:
+	close(fd);
+out_errno:
+	RC_CHK_ACCESS(dso)->load_errno = errno;
+	return -1;
+}
+
+bool symsrc__possibly_runtime(struct symsrc *ss __maybe_unused)
+{
+	/* Assume all sym sources could be a runtime image. */
+	return true;
+}
+
+bool symsrc__has_symtab(struct symsrc *ss __maybe_unused)
+{
+	return false;
+}
+
+void symsrc__destroy(struct symsrc *ss)
+{
+	zfree(&ss->name);
+	close(ss->fd);
+}
+
+int dso__synthesize_plt_symbols(struct dso *dso __maybe_unused,
+				struct symsrc *ss __maybe_unused)
+{
+	return 0;
+}
+
+static int fd__is_64_bit(int fd)
+{
+	u8 e_ident[EI_NIDENT];
+
+	if (lseek(fd, 0, SEEK_SET))
+		return -1;
+
+	if (readn(fd, e_ident, sizeof(e_ident)) != sizeof(e_ident))
+		return -1;
+
+	if (memcmp(e_ident, ELFMAG, SELFMAG) ||
+	    e_ident[EI_VERSION] != EV_CURRENT)
+		return -1;
+
+	return e_ident[EI_CLASS] == ELFCLASS64;
+}
+
+enum dso_type dso__type_fd(int fd)
+{
+	Elf64_Ehdr ehdr;
+	int ret;
+
+	ret = fd__is_64_bit(fd);
+	if (ret < 0)
+		return DSO__TYPE_UNKNOWN;
+
+	if (ret)
+		return DSO__TYPE_64BIT;
+
+	if (readn(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr))
+		return DSO__TYPE_UNKNOWN;
+
+	if (ehdr.e_machine == EM_X86_64)
+		return DSO__TYPE_X32BIT;
+
+	return DSO__TYPE_32BIT;
+}
+
+int dso__load_sym(struct dso *dso, struct map *map __maybe_unused,
+		  struct symsrc *ss,
+		  struct symsrc *runtime_ss __maybe_unused,
+		  int kmodule __maybe_unused)
+{
+	struct build_id bid = { .size = 0, };
+	int ret;
+
+	ret = fd__is_64_bit(ss->fd);
+	if (ret >= 0)
+		RC_CHK_ACCESS(dso)->is_64_bit = ret;
+
+	if (filename__read_build_id(ss->name, &bid) > 0)
+		dso__set_build_id(dso, &bid);
+	return 0;
+}
+
+int file__read_maps(int fd __maybe_unused, bool exe __maybe_unused,
+		    mapfn_t mapfn __maybe_unused, void *data __maybe_unused,
+		    bool *is_64_bit __maybe_unused)
+{
+	return -1;
+}
+
+int kcore_extract__create(struct kcore_extract *kce __maybe_unused)
+{
+	return -1;
+}
+
+void kcore_extract__delete(struct kcore_extract *kce __maybe_unused)
+{
+}
+
+int kcore_copy(const char *from_dir __maybe_unused,
+	       const char *to_dir __maybe_unused)
+{
+	return -1;
+}
+
+void symbol__elf_init(void)
+{
+}
+
+bool filename__has_section(const char *filename __maybe_unused, const char *sec __maybe_unused)
+{
+	return false;
+}